Why the two sql result is different?

[翊玮 赵]

IN Mysql 8.0.26， the following two select sql result is different, why?


CREATE TABLE testjs(js json);

CREATE TABLE testtext(tx text);

INSERT INTO testjs values('"abc"');

INSERT INTO testext values('abc');


SELECT js = tx FROM testjs, testtext;
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1


SELECT * FROM testjs, testtext WHERE js = tx;
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empty set


IS the compare in where clause caused different?